An existing off-road vehicle is equipped with eight road wheels carried on swingable suspension arms (four on each side of the vehicle); each road wheel can be driven by a chain or gear drive contained within the associated suspension trailing arm. It was thought that the vehicle could have improved mobility in soft terrain by providing endless treads or tracks around selected ones of the wheels, in the manner shown for example in U.S. Pat. No. 3,299,978 issued to W. B. Sponsler (see FIG. 6). However, problems in maintaining a degree of suspension and also track tension arose because the existing vehicle design provided for independent swinging movement of each suspension arm in accordance with momentary changes in the terrain; under certain conditions the wheel centerline spacing could be shortened sufficiently to produce track slack, possible untracking, and possible spinning of the wheels within the track.
The present invention is intended to provide an extensible connector between the wheels for maintaining wheel centerline spacing equal to the centerline spacing of the upper pivot points of the trailing arms, thereby creating a parallelogram arrangement that maintains a degree of suspension while preventing excessive looseness or play in the track. At the same time the connector accepts the compressive loads created by the track, thereby relieving loads on the wheel bearings.